Motoric Cognitive Risk Syndrome: Predictor of Dementia and Age-Related Negative Outcomes

Motoric cognitive risk syndrome and incident dementia: results from a population-based prospective and observational cohort study

BACKGROUND AND PURPOSE

Motoric cognitive risk syndrome (MCR), which is the juncture of subjective cognitive complaint and slow gait speed, is a pre-dementia stage. The aims of the study are (i) to compare characteristics between individuals who have MCR defined using slow walking speed and/or increased five-times-sit-to-stand (FTSS) time as its motor component(s); and (ii) to characterize the association of MCR and its various motor components with incident dementia including Alzheimer disease and non-Alzheimer dementia in the participants of the Epidémiologie de l'Ostéoporose (EPIDOS) study.

METHODS

This prospective and observational cohort study selected 651 participants recruited from the EPIDOS study in Toulouse (France). MCR was defined as the association of subjective cognitive complaint and slow gait speed and/or increased FTSS time in participants without either dementia and mobility disabilities at baseline. Individuals with dementia were prospectively diagnosed during the physical and neuropsychological assessments included in the 7-year follow-up.

RESULTS

The prevalence of MCR was around 7% when using an exclusive motor criterion, either slow gait speed or increased FTSS time, and was 20.9% when MCR subgroups were pooled. MCR was positively associated with incident dementia regardless of its type, and with Alzheimer disease in the slow gait speed MCR subgroup [odds ratio (OR) > 2.18 with P ≤ 0.037] but not with non-Alzheimer dementia. No significant association between incident dementia and MCR defined using increased FTSS time was shown.

CONCLUSIONS

Our findings confirm that MCR is associated with incident dementia and that slow gait speed is the appropriate motor criterion for detecting dementia risk.

Prevalence, incidence, and clinical impact of cognitive-motoric risk syndrome in Europe, USA, and Japan: facts and numbers update 2019

A new syndrome called the 'motoric-cognitive risk' (MCR) syndrome has recently been proposed in older persons. According to this definition, the parallel impairment in muscle and brain function is more predictive for identifying subjects at risk of dementia than impairment a in single system alone. Epidemiological studies suggest that among older persons, enrolled in worldwide population-based studies, 10% are affected by this syndrome, which confers a higher risk of future disability. In detail, the prevalence of MCR in Europe is around 8.0%, 7.0% in the United States, and 6.3% in Japan. The incidence of the MCR syndrome is estimated to be 65.2 per 1000 person years in adults aged 60 years or older. Many studies reported negative outcomes of the syndrome in older persons, emphasizing its clinical impact. In particular, in almost all longitudinal studies, MCR produces a three-time increased risk of future dementia. In Europe, data from the InCHIANTI study report an increased risk of 2.74 [1.54-4.86], which is 2.49 [1.52-4.10] in the United States and 3.27 [1.55-6.90] in Japan. The studies in different continents are also consistent in showing an increased risk of all-cause mortality, which is 1.50-1.87 in the Europeans and 1.69 [1.08-2.02] for incident disability in Japan. For the identification of the MCR syndrome, different tests and procedures have been proposed, with a final 'core-battery' that includes gait speed, dual-task gait speed, the Montreal Cognitive Assessment and Trail Making Test A and B. The criteria used to select this core-battery were based on the best accuracy for identifying older persons at risk of negative outcomes such as dementia, falls, aging-related disabilities, and sensitivity to interventions. The selection of these tests will allow to start studies aimed to better capture older persons at higher risk of mobility and cognitive disability. By these tests, it will be possible to better evaluate the effect of treatment composing of tailored physical exercise, nutritional suggestions, and medical therapy to overturn negative effect of both cognitive and motoric frailty. This article provides an overview of the current knowledge of the MCR syndrome.

Dementia in Down syndrome: unique insights for Alzheimer disease research

Virtually all adults with Down syndrome (DS) show the neuropathological changes of Alzheimer disease (AD) by the age of 40 years. This association is partially due to overexpression of amyloid precursor protein, encoded by APP, as a result of the location of this gene on chromosome 21. Amyloid-β accumulates in the brain across the lifespan of people with DS, which provides a unique opportunity to understand the temporal progression of AD and the epigenetic factors that contribute to the age of dementia onset. This age dependency in the development of AD in DS can inform research into the presentation of AD in the general population, in whom a longitudinal perspective of the disease is not often available. Comparison of the risk profiles, biomarker profiles and genetic profiles of adults with DS with those of individuals with AD in the general population can help to determine common and distinct pathways as well as mechanisms underlying increased risk of dementia. This Review evaluates the similarities and differences between the pathological cascades and genetics underpinning DS and AD with the aim of providing a platform for common exploration of these disorders.

Royal Jelly Delays Motor Functional Impairment During Aging in Genetically Heterogeneous Male Mice

Aging is associated with motor disorders that decrease the quality of life (QOL). Royal jelly (RJ), used as a dietary supplement, has shown various health benefits and, therefore, it has the potential to improve the QOL during aging. We have previously developed protease enzyme-treated RJ to avoid the anaphylactic response induced by RJ supplementation. However, the effects of a lifelong treatment with RJ on normal aging have not been fully clarified. In this study, we investigated the effects of enzyme-untreated RJ (NRJ) and enzyme-treated RJ (ERJ) on the aging process focusing on motor functions, by using a genetically heterogeneous (HET) mouse model experimentally endowed with genetic diversity. We performed four different physical performance tests (grip strength, wire hang, horizontal bar, and rotarod). We showed that the age-related impairment of the motor functions was significantly delayed in RJ-treated mice. Both NRJ and ERJ were similarly effective against these types of aging-associated declines. Histological analyses revealed that the RJ treatment affected the muscle fiber size at an advanced age. We also demonstrated that age-related changes in muscle satellite cell markers and catabolic genes were affected in RJ-treated mice. These results suggest that non-protein components of RJ improved the motor function in aging mice. These findings indicate that RJ has the potential to change the QOL during aging by regulating the motor function.

[Cognition and mobility : The influence of the brain on gait]

Cognitive abilities and gait with its physical parameters are important for mobility. There is clinically sound evidence that a reduction of gait speed can be seen as an early subclinical indicator of cognitive decline of even higher risk of onset of dementia. The dual-task paradigm is a method in which the older person has to simultaneously solve two different task. It is of utmost importance to identify older persons at risk of falls or onset of dementia. The dual-task paradigm seems to be an important method in this process.